[Solved] The output of ls with -aF option is not clear

Question

When you use ls, you are reading a directory file, not actually looking in a directory. Every directory listing contains an entry for the present/current directory, as well as its parent directory, just as you would expect to also see listings for sub/child directories in any directory listing.

The -A option for ls merely tells ls to display ALL files, which includes the entries of ./ & ../ for present and parent. Note that these dots are merely a shorthand that the shell (bash) uses to represent file paths for those files. In other words, what “./” really means is say ~/Desktop if you were currently in the Desktop directory doing an ls. And “../” would mean “~/” which is just another symbolic shorthand to represent your user home directory, which is probably something like /Users/your_username on macOS (OS X), or /usr/your_username for various Linux distributions. Note that those paths could also be written with the forward slash appended at the end and would mean the same thing (e.g., /Users/your_username/ is the same as /Users/your_username because they are both references to other directories (directory files).

Use the -a option for ls if you don’t want to see ./ & ../, but still want to see (other) hidden files.

Using the -F option causes ls to display appended characters to the file types based on the file type. This is why directories are displayed with the forward slash appended at the end, and executables are displayed as executable* (with the asterisk appended), and regular files have no appendage (e.g., .txt, .png, .dmg).

Accepted Answer

When you use ls, you are reading a directory file, not actually looking in a directory. Every directory listing contains an entry for the present/current directory, as well as its parent directory, just as you would expect to also see listings for sub/child directories in any directory listing.

The -A option for ls merely tells ls to display ALL files, which includes the entries of ./ & ../ for present and parent. Note that these dots are merely a shorthand that the shell (bash) uses to represent file paths for those files. In other words, what “./” really means is say ~/Desktop if you were currently in the Desktop directory doing an ls. And “../” would mean “~/” which is just another symbolic shorthand to represent your user home directory, which is probably something like /Users/your_username on macOS (OS X), or /usr/your_username for various Linux distributions. Note that those paths could also be written with the forward slash appended at the end and would mean the same thing (e.g., /Users/your_username/ is the same as /Users/your_username because they are both references to other directories (directory files).

Use the -a option for ls if you don’t want to see ./ & ../, but still want to see (other) hidden files.

Using the -F option causes ls to display appended characters to the file types based on the file type. This is why directories are displayed with the forward slash appended at the end, and executables are displayed as executable* (with the asterisk appended), and regular files have no appendage (e.g., .txt, .png, .dmg).